ACS::WaitFor - 运维编排服务

用途

使用该动作可以等待资源进入预期的状态。通过调用云产品的OpenAPI去查询指定资源的状态，直到资源的状态和预期的一致。如通过调用ECS的OpenAPIRunInstances创建资源后，可以通过调用ACS::WaitFor等待实例被创建完成，即其状态为运行中（Running）。

语法

Tasks:
  - Name: waitForTaskExample
    Action: ACS::WaitFor
    Properties: 
      # 以下属性和ACS::ExecuteAPI一致，请参考ACS::ExecuteAPI语法说明。
      Service: ECS
      API: DescribeInstances
      Parameters: 
        InstanceId: i-12345678abcedfg
      # 以下属性为ACS::WaitFor的特殊属性
      PropertySelector: "jq selector" # 必填，需要等待的具体的API返回值，参考ACS::ExecuteAPI中的ValueSelector说明
      StopRetryValues: # 可选，一旦任务PropertySelector结果为status1状态时终止任务等待及API重试。比如status1为'Stopped'时，一旦API返回结果筛选后为Stopped，则该任务执行停止。
        - status1
      DesiredValues: # DesiredValue，NotDesiredValues 必填其一，指上面截取的值要匹配到以下值之一，匹配则表示成功，否则会超时然后失败。
        - value1
        - value2
      NotDesiredValues: # DesiredValue，NotDesiredValues 必填其一，指上面截取的值要不匹配到以下的所有值，全都不匹配则表示成功，否则会超时然后失败。
        - value3
        - value4
    Retries: maxRetryTimes # 可选，表示最大重试次数，填写正整数，如5。重试间隔时间依次为1s、2s、4s、8s ...，随已重试次数指数变化。
    Outputs:  # WaitFor动作所在的任务支持输出，当任务满足NotDesiredValues/DesiredValues的条件时，任务执行成功后会返回输出参数的值。
      OutputParameter1:
        ValueSelector: 'jq selector' # jq的选择器语法，以OpenAPI的返回作为JSON输入，jq的语法请参考 https://stedolan.github.io/jq/
        Type: String/Boolean/List(Array)/Number/Object

• JSON格式（请参考YAML注释说明）

{
  "Tasks": [
    {
      "Name": "waitForTaskExample",
      "Action": "ACS::WaitFor",
      "Properties": {
        "Service": "ECS",
        "API": "DescribeInstances",
        "Parameters": {
          "InstanceId": "i-12345678abcedfg"
        },
        "PropertySelector": "jq selector",
        "StopRetryValues":["status1"],
        "DesiredValues": [
          "value1",
          "value2"
        ],
        "NotDesiredValues": [
          "value3",
          "value4"
        ]
      },
    "Outputs": {
        "OutputParameter1": {
          "ValueSelector": "jq selector",
          "Type": "String/Boolean/List(Array)/Number/Object"
        }
      }
    }
  ]
}

示例

如下模板：启动一台指定实例，通过调用WaitFor等待实例的状态变为Running。

• YAML格式：

---
FormatVersion: OOS-2019-06-01
Parameters:
  InstanceId:
    Description: the instance id that you will start.
    Type: String
Tasks:
- Name: startInstance
  Action: ACS::ExecuteAPI
  Description: start instance with specified parameters
  Properties:
    Service: ECS
    API: StartInstance
    Parameters:
      InstanceId: '{{ InstanceId }}'
- Name: untilInstanceReady
  Action: ACS::WaitFor
  Description: describe instances with specified parameters
  Properties:
    Service: ECS
    API: DescribeInstances
    Parameters:
      InstanceIds:
      - '{{ InstanceId }}'
    PropertySelector: Instances.Instance[].Status
    DesiredValues:
    - Running

• JSON格式：

{
    "FormatVersion": "OOS-2019-06-01",
    "Parameters": {
        "InstanceId": {
            "Description": "the instance id that you will start.",
            "Type": "String"
        }
    },
    "Tasks": [
        {
            "Name": "startInstance",
            "Action": "ACS::ExecuteAPI",
            "Description": "start instance with specified parameters",
            "Properties": {
                "Service": "ECS",
                "API": "StartInstance",
                "Parameters": {
                    "InstanceId": "{{ InstanceId }}"
                }
            }
        },
        {
            "Name": "untilInstanceReady",
            "Action": "ACS::WaitFor",
            "Description": "describe instances with specified parameters",
            "Properties": {
                "Service": "ECS",
                "API": "DescribeInstances",
                "Parameters": {
                    "InstanceIds": [ "{{ InstanceId }}"]
                },
                "PropertySelector": "Instances.Instance[].Status",
                "DesiredValues": [ "Running" ],
            }
        }
    ]
}